On Monday 12th March, the Prime Minister of Great Britain and Northern Ireland, Theresa May, stood up in Parliament and made the following claim as part of her 36-hour ultimatum to the Russian Federation:

“Mr Speaker, this morning I chaired a meeting of the National Security Council in which we considered the information so far available. As is normal, the Council was updated on the assessment and intelligence picture, as well as the state of the investigation.

It is now clear that Mr Skripal and his daughter were poisoned with a military-grade nerve agentof a type developed by Russia. This is part of a group of nerve agents known as ‘Novichok’.

Based on the positive identification of this chemical agent by world-leading experts at the Defence Science and Technology Laboratory at Porton Down; our knowledge that Russia has previously produced this agent and would still be capable of doing so; Russia’s record of conducting state-sponsored assassinations; and our assessment that Russia views some defectors as legitimate targets for assassinations; the Government has concluded that it is highly likely that Russia was responsible for the act against Sergei and Yulia Skripal [my emphasis].”

“Mr Speaker, on Monday I set out that Mr Skripal and his daughter were poisoned with a Novichok: a military grade nerve agentdeveloped by Russia [my emphasis].”

Let’s break this down. The three key parts of Mrs May’s claim are as follows:

1) That the experts at Porton Down had made a positive identificationof the substance used to poison Mr Skripal and his daughter, Yulia.

2) That this positive identification concluded that it was a military-grade nerve agent.

3) That this positive identificationwas that the substance was part of a group of nerve agents known as ‘Novichok’.

In a judgement at the High Court on 22nd March on whether to allow blood samples to be taken from Sergei and Yulia Skripal for examination by the OPCW, the evidence submitted by Porton Down (in section 17 i), stated the following:

“Blood samples from Sergei Skripal and Yulia Skripal were analysed and the findings indicatedexposure to a nerve agent or related compound. The samples tested positive for the presence of a Novichok class nerve agent or closely related agent[my emphasis].”

Let’s break this down. The three key parts of the evidence given by Porton Down to the High Court are as follows:

1) That the analysis at Porton Down indicatedthe substance used to poison Mr Skripal and his daughter, Yulia.

2) That this indicationwas not able to positively identifywhether the substance used was actually a nerve agent (much less a military-grade nerve agent), and left open the possibility that it may have been a related compound.

3) That this indicationcould not positively identifywhether the substance was part of a group of nerve agents known as ‘Novichok’, or whether it was a closely related agent.

Mrs May’s statement claims positive identification of a military grade nerve agent of the “Novichok” class of chemical weapons. Porton Down’s evidence to the High Court shows that no such positive identification took place.

Two statements. Both cannot be true.

I do not know who poisoned the Skripals, how it was done, or for what reason. I continue to keep an open mind. But I do know one thing. It looks like Mrs May has some explaining to do.